                        Astronomy Picture of the Day

    Discover the cosmos! Each day a different image or photograph of our
      fascinating universe is featured, along with a brief explanation
                    written by a professional astronomer.

                                2023 July 11
      Our Sun is pictured with hundreds of dark sunspots. The image is
    actually a composite of all of the sunspots visible during the first
       half of this year. Please see the explanation for more detailed
                                information.

                          Sunspots on an Active Sun
        Image Credit: NASA, SDO; Processing & Copyright: Şenol Şanlı

   Explanation: Why is our Sun so active now? No one is sure. An increase
   in surface activity was expected because our Sun is approaching solar
   maximum in 2025. However, last month our Sun sprouted more sunspots
   than in any month during the entire previous 11-year solar cycle -- and
   even dating back to 2002. The featured picture is a composite of images
   taken every day from January to June by NASA's Solar Dynamic
   Observatory. Showing a high abundance of sunspots, large individual
   spots can be tracked across the Sun's disk, left to right, over about
   two weeks. As a solar cycle continues, sunspots typically appear closer
   to the equator. Sunspots are just one way that our Sun displays surface
   activity -- another is flares and coronal mass ejections (CMEs) that
   expel particles out into the Solar System. Since these particles can
   affect astronauts and electronics, tracking surface disturbances is of
   more than aesthetic value. Conversely, solar activity can have very
   high aesthetic value -- in the Earth's atmosphere when they trigger
   aurora.

                   Tomorrow's picture: star bar with rings
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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Phillip Newman Specific rights apply.
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                      A service of: ASD at NASA / GSFC,
                           NASA Science Activation
                             & Michigan Tech. U.

